Evaluation of Efflux Pump MexAB-OprM of Pseudomonas aeruginosa Strains Isolated from Clinical Samples in Zahedan

Background: Pseudomonas aeruginosa is one of the most common nosocomial pathogens with high mortality rates. Organisms such as Pseudomonas aeruginosa have the ability to develop high level MDR. The Mex AB-OprM system is one of the largest multidrug resistence efflux pumps in P.aeruginosa. The aim of this study was to evaluate the frequency and determine the efflux pumps in clinical strains of Pseudomonas aeruginosa isolated from zahedan hospitals.Methods: In this cross-sectional study, during 9 months period, 200 samples were collected from different parts of 3 hospitals in Zahedan using targeted sampling. biochemical tests were performed to identify the species and antibiotic susceptibilities by Kirby-Bauer disk diffusion protocol.Furthermore MIC method was performed for imipenem,ceftazidime and piperacillin tazobactam.finally PCR was used for determining the efflux pump genes evaluate.Results:Among 10 selected antibiotics , the greatest resistance was to ciprofloxacin(37%) and the lowest one to ceftazidime(6%) and piperacillin tazobactam(6/5%). The most isolated strain was urine specimen (54%). All strains were also susceptible to colitis. The molecular evaluation of the pumps showed the presence of the mex A and mex B genes were in 169 (84/5%) and 157 (78/5%), and the OprM gene were 49% .Conclusion: Although efflux pumps Mex AB-OprM plays an important role in antibiotic resistance in P.aeruginusa becausw of acting the efflux pumps on antibiotic in a non-specific manner,it is elusive to consider or describe an antibiotic resistance based on the presence of an efflux pump.

Keywords:

Pseudomonas Aeruginosa , Antibiotic Resistance , efflux system